There is great interest in providing existing infrastructures for wireless communication systems with the capability for locating people and/or objects in a cost effective manner. Such a capability would be invaluable in a variety of situations, especially in emergency, crime situations and mobile commerce. There are numerous competing wireless location technologies that purport to effectively locate wireless mobile stations (as used herein this term includes, e.g., mobile phones, short message devices (SMS), electronic container tracking tags, micro-transceivers for personal location and/or emergency, and mobile transmitters such as can be used on battlefield or military reconnaissance, surveillance or tracking; additionally, in a more general context, this term includes vehicles, and other mobile units such as railroad cars, watercraft, and aircraft containing a device that can be located wirelessly). These technologies can be generally classified as:                (a) handset centric wherein a portion of the location processing is performed at the mobile stations, and in particular, each such mobile station (MS) includes specialized electronics specifically for performing location. In most cases, such specialized electronics are for detecting and receiving satellite (or more generally, non-terrestrial transmitters and/or transceivers) signals that can then be used in determining a location of the MS;        (b) network centric wherein the wireless communication network(s) with which the MS is in contact handle substantially all location specific processing. As one skilled in the art will understand, there are various wireless location technologies that are available such as location technologies based on time difference of arrival (TDOA), time of arrival (TOA), timing advance (TA) techniques, angle of arrival (AOA), multipath pattern matching techniques; and        (c) hybrid systems wherein there are specialized location electronics at the handset (“handset” being used herein as an equivalent to mobile station unless stated otherwise), but a non-trivial amount of the location processing is performed at a network site rather at the MS. An example of such a hybrid system is what is known as network assisted GPS systems, wherein GPS signals are obtained at the MS (with the assistance network received information) and GPS timing information is transmitted from the MS to the network for performing MS location computations.        
The wide variety of wireless location techniques can provide, under appropriate circumstances, the following advantages:                (a) if the techniques are used in combination, a more reliable and accurate wireless location capability can be provided. In particular, when an embodiment of one wireless location technique is known to be less than satisfactory in a particular geographic area, an alternative embodiment (or alternative technique) can be used to obtain an MS's location(s). Additionally, two different embodiments and/or techniques can be applied substantially simultaneously for locating an MS. In this latter case, a location resolver is likely needed to determine a “most likely” resulting MS location estimate. Note, that wireless location systems for combining wireless location techniques is described in the following international and U.S. patent applications which are each incorporated fully by reference herein:                    i. U.S. Provisional Patent Application No. 60/025,855 filed Sep. 9, 1996;            ii. U.S. Provisional Patent Application No. 60/044,821, filed Apr. 25, 1997;            iii. U.S. Provisional Application No. 60/056,590, filed Aug. 20, 1997;            iv. International Patent Application No. PCT/US97/15933 filed Sep. 8, 1997 entitled “LOCATION OF A MOBILE STATION USING A PLURALITY OF COMMERCIAL WIRELESS INFRASTRUCTURES” by LeBlanc, Dupray, and Karr;            v. International Patent Application No. PCT/US97/15892 filed Sep. 8, 1997; entitled “LOCATION OF A MOBILE STATION” by Dupray, and Karr            vi. U.S. patent application Ser. No. 09/194,367 filed Nov. 24, 1999 entitled “Location Of A Mobile Station” by Dupray, and Karr;            vii. U.S. patent application Ser. No. 09/176,587 filed Oct. 21, 1998 entitled “Wireless Location System For Calibrating Multiple Location Estimators” by Dupray;            viii. U.S. Pat. No. 6,236,365 filed Jan. 22, 1999 entitled “Location of a Mobile Station Using A Plurality Of Commercial Infrastructures” by LeBlanc, Dupray and Karr;            ix. U.S. Pat. No. 6,235,365 filed: Apr. 23, 1999 entitled “WIRELESS LOCATION USING MULTIPLE LOCATION ESTIMATORS” by Dupray; and            x. International Patent Application No. PCT/US01/17957 filed Jun. 4, 2001 entitled “A Wireless Location Gateway And Applications Therefor” by Dupray; and                        (b) if a primary wireless location technique fails (e.g., due to an electronics malfunction), then assuming an alternative technique is available that does not use, e.g., the malfunctioning electronics of the primary technique, then the alternative technique can be used for MS location.        
However, the variety of wireless location techniques available is also problematic for at least the following reasons:                (a) a request for an MS location can require either the requester to know the wireless location service provider of the geographical area where the MS is likely to be, or to contact a location broker that is able to, e.g., determine a communication network covering the geographical area within which the MS is currently residing and activate (directly or through the MS's wireless service provider) an appropriate wireless location service. In the art, the technology enabling such a location broker capability has been referred to as a “wireless location gateway”. An embodiment of such a gateway is described in the PCT/US97/15892 reference identified above;        (b) for communication networks relying on handset centric and/or hybrid systems for MS location, MSs roaming from networks using only network centric location capabilities will likely not have the specialized electronics needed for being located, and accordingly many location related network services will not be available such as emergency services (e.g., E911 in the U.S.).        (c) different location techniques have different reliability and accuracy characteristics. Thus, the wireless location technology may need to be selected according to the requirements of the location requesting application. For example, location requesting applications that require relatively precise location information are emergency rescue, and certain military related applications (e.g., battlefield data fusion, battlefield maneuvers and/or military command, control and communication (C3)).        
Accordingly, it would be desirable to integrate into a single wireless location broker or wireless location gateway as many location techniques as possible (or commercially feasible) so that location requests can be fulfilled without the requester needing to know what location technique is used. It would be further desirable for roaming MSs to be able to be located in coverage areas where a wireless location technique is different from the one (or more) techniques supported in the primary subscription area for the MS. Additionally, it would be desirable to provide new applications for which MS location information can be applied via, e.g., a wireless location gateway.